Disrupted Glutamate Signaling in Generates Locomotor Rhythms in Constant Light.

We have used the Cambridge Protein Trap resource (CPTI) to screen for flies whose locomotor rhythms are rhythmic in constant light (LL) as a means of identifying circadian photoreception genes. From the screen of ∼150 CPTI lines, we obtained seven hits, two of which targeted the glutamate pathway, and We focused on these by employing available mutants and observed that variants of these genes also showed high levels of LL rhythmicity compared with controls. It was also clear that the genetic background was important with a strong interaction observed with the common and naturally occurring polymorphisms, and The less circadian photosensitive allele generated high levels of LL rhythmicity in combination with or , even though and alleles do not, by themselves, generate the LL phenotype.